Final answer:
Chapters 27 and 28 of To Kill a Mockingbird depict Bob Ewell's threatening actions post-trial and the Halloween festival, culminating in Bob's attack on Scout and Jem and his subsequent death.
Step-by-step explanation:
The main events of chapters 27 and 28 in To Kill a Mockingbird focus on the aftermath of the trial and the Halloween festival. In Chapter 27, Bob Ewell's behavior becomes increasingly threatening, as he loses his job and blames Atticus for his problems, attempts to break into Judge Taylor's house, and follows Helen Robinson to work, demonstrating his vengeful nature after the trial. Chapter 28 describes the Halloween pageant at the school in which Scout plays a ham. It also covers the tense walk home where Scout and Jem are attacked by Bob Ewell, leading to a struggle in which it is implied that Bob Ewell is killed and Boo Radley saves the children.